F•X

So, what is F•X and what is it that makes it so special?

Let us first look at a representative range of arms to see what it is we are trying to better.
(We are looking for a straight line, at the bottom.
How closely do they achieve this?)

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Here we have a resonance curve from a very well known arm, long been considered a world reference or indeed the "best" arm in the world.

Note the very high amplitude peak sticking out like a very sore thumb.

Even with damping the energy trend is still be seen.

The cost for this arm? £3,000
This curve is from an even more expensive, very highly developed "super-arm" from another respected manufacturer. By conventional standards, the results are considered very good.

Despite its complex tube construction, multiple spikes exceeding10dB are still in evidence.


The cost of this arm? £3,500.
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The next three arms are all more affordably priced in the region of £500-£1500.
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This particular curve is representative of the performance of the arms available today with metal tube construction.

Such a response has a characteristic signature and masks detail.
This arm is based on modern materials - Carbon Fibre.

Multiple HF peaks accentuate the arm's sonic signature and with one peak exceeding 30dB,

Being a woven construction, one could anticipate a well damped behaviour, so clearly this is not the case.

Pickup arm design is more complex than it would at first appear.
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This final curve is from a most popular range of metal arms!


Again, the similarity in bending modes to previous curves and the height of the peaks demonstrates clearly the underlying problem of the conventional metal 9" arm.

Is it any wonder none of these manufacturers display these curves!
The above curves all represent whatever the arm is that you have been listening to over past decades.
The graphs are all equivalent in terms of scale.
They are not specially selected to show one or other at its worst.
They have not been "doctored" in any way.

Such large spikes means that all are strongly characterful.
Establishing which is "better" is not easy and can only come down to personal preference.

"
But how is this? Aren't tubes stiff?"
The above curves shows us that they aren't.
It is the very simplicity of a tube which leads us to "believe" them to be rigid.
But like wind chimes, they "ring".
£200, £2,000, £3,500 it makes little difference - if they are tubular, they cannot help but ring.

Let us consider a loudspeaker:
A well-designed and likeable speaker typically achieves a responses of +/- 3dB.
Would you then listen to, let alone buy a speaker with a response of +/- 15 dB? No way!

And yet from the above we can see that the tonearms we have all been listening to, without exception, all have a poor, no an abysmally poor performance...
and we consider them good!

To be blunt, reading other manufacturer's websites, they are all strong on waffle about "measuring the groove" but if they are all so correct, then simple measurements would simply support their contentions.
So, where's is the actual science? Nowhere.
Well, man did not get to the moon on waffle!

Fortunately this sorry state of affairs is now at and end.

Now let us see what the future holds...and there's no going back.

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Taken from HiFi World, this really is the curve of FX-R.

No crazy peaks. No HF spikes.
all with no damping.
Simply, no energy!
At + / - 3dB, only FX-R is comparable with that of a speaker's response.

This arm ought to sound dramatically different to all others.
HiFi Choice concluded FX-R outperformed the SME V.
"Giant slaying performance"

As to "why?", then read on...


The answer...techy bits (sort of)

Clearly we need a better mental picture to help us accept what is happening.


"
What if we stuff them full of damping? Won't that deal with the problem?"
1. Damping increases the mass of the tube - not a good thing.
2. It doesn't solve the problems with the main bending modes.
3. The sound doesn't improve, in fact it becomes leaden and dead.

We all know Carbon Fibre is stiff.
Look then at a 'stiff' fishing rod and we'll add a weight at the end.
To all intents and purposes this is an exact equivalent to our arm.
The difference is merely one of scale - things happen at a much lower frequency, which allows us to see things better, BUT make no mistake, they still happen!


First, we'll try twisting the rod. It takes two hands, but try it. Nothing happens. It really is stiff.
Now, how about
flexing it. You can hold the rod in one hand and it will obediently bounce: up - down or left - right and by very large amounts.
To damp this action, you can try wrapping bandages around the tube but no amount of rubber strips or whatever will stop the flexing.
In this instance,
Damping simply does not work.
But how does this relate to playing records?

Recall the flexing of the fishing rod? Well, the groove pushes the stylus up and down (left and right) as it tracks.
It is NOT like trying to twist it.
So our cartridge is sending energy
along the arm tube where as we have seen tube (arm) behaviour is very poor.
Our model really works and we can see how those resonant curves exist - and also that they are not easy to stop.

But there is worse to come.


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A "Perfect" Arm.
First Bending Mode

First bending mode - shown in red



The stylus is now not at its correct tracing angle.

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Higher order bending modes

Resonant flexing of the tube shortens its effective length as shown

The cartridge moves. The geometry alters.

As can be seen, a dramatic consequence to resonance / tube flexure is that the arm actually gets shorter, altering our geometry, affecting the tracing!

Not only are the problems so much worse than we thought, in over 100 years of arm design, not one single manufacturer or designer has highlighted these problems.

Is it any wonder other arms sound so bad?
Having shown how poor the conventional arm is, we had to totally re-think the way we support the cartridge.
Funk has done just that and come up with a radically elegant solution.
F•X (F dot cross)
F•X has a precision internal cross beam bracing construction (pat pending).
It is orders of magnitude stiffer in
all directions than a simple tube.

W
e get the above response curve without recourse to any damping.

With
F•X there is no penalty.
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Universally, arms are "distributed mass" designs.
The majority of the mass is distributed along the tube itself.
From the above curves we can see they are arguably poor.

Funk F.X system (FX3 and FX-R), is by contrast, a "lumped" mass design and using state of the art modelling (below), we can see immediately the benefit of Funk's F.X tube behaviour



Intentionally, then, it has a low effective mass.
FXR II pedestal


"But don't moving coils need a higher mass arm?"
What they need is not "higher mass", it is "optimum" mass.
Achieving this with
FX-R is simple:
Add mass to the headblock to match to the cartridge.

We have seen that spending £3,500 is no guarantee of performance.
With an unbalanced design, ABEC 20 bearings (if there were such a thing) are irrelevant.
If your arm resonates, it is in trouble.
All simple tubes resonate. Period.

"But. But. BUT! I've been told really, that bearings really are REALLY important. Really.
JUST
WHO doI believe?
And How can YOU (funk) be correct?"

Funnily enough, we've read similar comments on at least two different sites, so, Yes, TELL US ABOUT IT!
Manufacturers may keep going on...AND ON...AND ON about their fantastic bearings.
Is that ALL these manufacturers have to talk about?
Where's the darned science for the whole product?
(Anyway, so what? Even the best bearings are relatively cheap, so what has that to do with
anything?)

Just ask yourself: Is that
really where the action is occurring?
Doesn't it all happen at the
stylus first? Then the tube and then finally it gets to the bearings? Sorry, but by then the (sonic) damage has been done!

Hopefully by now you've got the idea:
The tube is resonating way before that! I.e. it is flopping about like a jelly.
What good are your perfect bearings now? They are at the opposite end of the cartridge. The energy has first to get to the opposite end of the tube before bearings matter a jot!

Just get the design right in the first place.
(...Oh. And if it makes you feel better, we use great bearings ourselves in F5 and FX3, anyway!)


Let's try a final, simple analogy.
Take a hypothetical performance car: the chassis that isn't all that stiff but it has fantastic wheel bearings.
Once road vibration gets into the chassis and excites it, it flexes and the handling is severely compromised. Bearings or no bearings.

The reality is that modern performance car designers spend inordinate amounts of effort ensuring the
chassis is indeed stiff: Ferrari FF, Audi R8, Jaguar type F and so on...(and also that they are light!)

Funk's FX3's stiff F•X beam construction and total balanced design follows such a time consuming design ethos.

As with a performance car on a race track that excels, with FX3 both measurement and listening tests show that F.X also works brilliantly!